Photographic shutter



`P. I. MARKS. PHOTOGRAPHIC SMITH-1R.` y V APPLICATION FILED OCT. 27, I9I9. I 1,422,460, Patented July 1l, 1922.

5 SHEETS-SHEET I.

l [Iv VENTO/e ATTORNEY P. 1. MARKS.' PHOTOGRAPHIC SHUTTER.

APPLlCATlON FILED 0CT.27,1919.

1,422,460,v APafuexvlced July 11, 1922.

v 5 SHEETS-SHEET 2.

r [Hy/wb www ATTORNEY fP. l. MARKS.

PHOTOGRAPHIE SHUTTER. APPLlATloN FILED OCT. 2, 1919.

' Patented Jury 11, 19'22.

5 SHEETS-SHEET 3.

lm i

W/TNESSES XM A TTORNEY P. '1. MARKS PHOTOGRAPHIC SHUTTER. x APPLICATION FILED OCT. 27, 1919. v 1,422,460, v l Patented July 11, 1922,

5 SHEETS-SHEET 4.

I/V/TNESSES: I l NVENTOR A TTORNE Y P. J. MARKS.

PHOTOGRAPHIC SHUTTER.

APPUCATION FILED OCT. 27. 1919.

1,422,460. Patented July 11, 1922.

5 SHEETS-SHEET 5.

an A TTO/e/VEY UNITED STATES PAUL J. MARKS', or 'n.ocniisrnn, NEW Yoan rnoroenarnio SHUTTER.

i Specification of Letters Patent.

i `Intenteiindy 11 iosa.

Application filed October 27, 1919. Serial No.` 333,838.

T0 LZZwiiomz't/may concern-f y Be it known that I, PAUL J. lvinns, a citizen oit' the United' States, residing at Rochester, in the ycounty ot' Monroe, State of New York, have invented certain new and useiiul Improvements in Photographic Shutters, and l do declare the lfollowing' to be a full, clear, and exact descriptionyot the same, reference being had to the accompanying drawings, forming a part ot this specilication.

` My invention relates to photographic shutters oi the kind used with cameras or other photographic instruments and has for its object to provide a shutter which is simple in construction and operation, automatic in action, not liable to get out ot order when in use and more etlicient than photographic shutters heretofore constructed. A lurther object of my invention is to provide a shutter having a casing which is. lightand strong, and which is strengthened by the diaphragm operating devices. Another object of my invention is to provide a shutter having an improved blade by means of which a greater volume oi light may be admitted during a given interval of time malring possible the Vfull-exposure of a photographic plate or film in a much shorter interval of time than hereto-tore. More specilically it is the object otmy invention to provide a shutter with blades so constructed that light will be admitted simultaneously from the center and outer margin et the opening during the opening and closing movements of the blades. Another object ot .my invention is to `provide a pivoted blade shutter in which the blades are constructed oi? thin material connected by devices ol thin liexible inatcri alto avoid shock and rebound and seiving as auxiliary blades to shut out the light at the Weak points When the shutter is closed `thus enabling me to employ narrow blades making possible the construction ot a light shutter o't' a high degree of etliciency 'for use on small cameras, having a small diameter `\vit.liout reducing the lens aperturethe auxvide a photogi'apliic shutter yivith improved i,{etarding devices whereby. accurately timed automatic exposures may be securedfrom the shortest fraction oi` secondto an automatically timed exposure ot several seconds duration. More specifically, l provide a retarder for a shut-ter which may be assembled as a `unit and Which comprises av plurality of dashpots or adashpot and a combined piston and dashpot, both dashpots operating ortlie longer automatic exposures While the movements tor the shorter exposures are selected from the longest range of movement required for the longest exposure. A still further object of my invention is to provide aretarder tor photographic shutters ot the cylinder and piston type on which the axis oi the cylinder is mounted in a position substantially parallel with the axis of the lens and which is there-` fore unitorin in action in all positions in which the camera be used. A still` further object of my :invention is to provide a photographic shutter having a re-, voluble 'dial for controlling the various speeds and which is at all times iree to be turned in eitliei direction- Without liability of breaking the parts or getting the shutter out of order. A still tui-ther object of my invention is to so construct the mechanism of a shutter that the trigger will be coinpletely returned to its normal position of rest When the blades are open for a time exposure thus overcoming the danger of displacing the cable release, which loosely eninl a socket' in the trigger. ,To these and other ends my invention resides `in certain i improvements, combinations and arrangement o'lf parts all as hereinai'terniore fully described and particularly pointed out in the appended claims.

In. the drawings i y Figure l. is a frontelevation'oft a photographic shutter constructed according tothe principles ofmy invention, n I

Figure 2 is a ,tr-ont elevation of the ysame with the cover removed to expose theparts and showing the blades openivith the ksetting devices set for a time exposure,

Figure 8- is a view similar to Fig. Q showing the position of the ger `has been released, y i n Figure t is a vieiv similar to Fig. y2 with partsbroken away, and showing the position of the parts When the vsetting devices are set tor bulb exposures and thek blades in open position,

parts after the trig-` CII Figure 5 is a view similar to Fig. 2 but showing the blades in closed position,

Figure 6 is a similar view with the setting devices set tor an automatic exposure of one tenth of a second,

Figure 7 is a view ot the casing broken away showing the retarding in position therein and the setting devices set for an automatic exposure of one second.

Figure 8 is a plan view ot the retarding devices removed from the casing,

`Figure 9 is plan view of the same, parts being removed,

Figure 10 is a side elevation o'l1 the retarding devices with the parts adjusted for an automatic exposure oil? one second,

Figure 11 is a central vertical section olI the retarding devices as seen in Fig. 10,

Figure 12 is a view similar to Fig. 11 with the parts adjusted 'for an automatic exposure 0f one-tenth oit a second.

Figure 18 is a similar view showing the parts adjusted ilor an automatic ei-:posure of the shortest duration oi? which the shntter is capable;

Figure 14!I is a vertical section ot a lever cooperating with the retarding devices,

Figure 15 is an enlarged sectional. view `through the cylinders oli the retarding devices,

Figure 1G is an enlarged view ot the set ting and cooperating devices, parts thereo'.l being shown in section,

,Figure 17 is a. plan view olf the setting` dial removed,

Figure 18 is an inverted plan view thereof,

Figures 19 and 2O are sections olB details showing the mounting oi the blade operating` member,

Figure 21 is a section through the shutter casing showing the mountings of the trigger, and the blade operating device,

Figure 22 a view ot the shutter with parts removed to show the blades and eonnecting parts, the blades being shown in closed position,

Figure 23 is a similar view showing` the blades alter 'the initial opening movement,

Figures 2l, 25 and 2G are similar views showing further movements of the blades to the l'ull open position,

Figures 27 and 28 are details oit the blade construction.

My improved shutter comprises a casing 1 of metal or other suitable ma erial from the rear side of which projects the lens barrel 2 having internal screw threads adapted to receive the rear combination oli a lens. The barrel 2 is also externally threaded 'to cooperate with that part oi" the camera. to which it is secured. Adjacent the barrel 2 the casing is provided with a recess best seen in Fig. 21 ot the drawings in which the iris diaphragm and connected parts are housed. At the rear side of the recess 8 the partly devices casing is slotted as at l and an inwardly and upwardly projecting lug 5 on the diaphragm operating member projects through this slot to cooperate with the diaphragm ring. F orwardly of the recess 3, the casing is enlarged to house the operating mechanism of the shutter. The lront of 'the shutter is closed by means ot a cover plate 6 suitably secured in position and providial with an internally threaded lens ba rrcl l'.

A ring 16 is seated in a groove 17 provided therefor in the outer wall oi the eas ing and provided with the projection or lug' which extends through a slot in the casing wall beneath the ring and engages the diaphragm ring. The ring 1G is provided with a pointer 19 which Ais bent up adjactmt the outer periphery oll the casing and cooperates with a scale 2O secured to, or formed on, the front wall oli the cover as shown in Fig. 1. rllhe scale is provided with the usual numerals 1, 8, 16 etc. to indicate the diaphragm openings the well known lll S. system or in terms o'lA the Y'ocal length oit the lens.

Suitably secured in the casing` is a plate or partition 21 having an aperture coni-entric with the diaphragm opening and which serves as a support ilior the shutter operating devices. The shutteil blades oli which there are 'three in number indicated by the relierence numerals 22, 23 and 241 are pivoted to the rear easing wall and operate between the ring`11 and the rear lince ol the partition 21. l show three blades in the p" 'mit instance athough it is to be understood thaY a. greater or less number may be used with out departing 'from tl spirit or scope olf my invention. The blades 22, 23 and 2i which we 'will designate as primarv olades are connected to operate sinniltaneonsly by lne-ans which serve to cooperate with the primary blades to complelel),Y close the aperture when the blades are in closed position. Said n'ieans are hereinafter more 'inlly described. and effectively prevents the relierl'ion oi' light about the edges ol the blades.

llach o'lx4 the blades 22. 23 and l is os" novel` construction and one is shown in detail in F ig. of the drawings. rl`he blades are made of thin material ot the vl'orm shown in F ig. 33, and pivoted to 'the casing to turn about the points 25 which are placed equidistantly trom each other. llhen the shutter is closed the blades occupy the positions shown in Fig. oi" the drawings, and successive vopening` positions are shown in Figs. 29, 30, 31 and 32 the last ligure sliow ing` the blades in the 'liully open position. l. have so constructed the blades that in the opening and closing movements light will be admitted simultaneously irom the center and periphery o'l the znicrture as clearly shown in Figs. 29, 30 and 31. For this purpose, each ot the blades 1s ent away as at 26 to iorm an opening tor ,admitting the light atA three eccentric points. as soon as the blades move the openings 26 past ,the ends ot the adjacent blades.y This occursas soon as the blades 'have moved sumciently to cause an opening at the center and continues until the blades have moved suliiciently to bring the openings26 outside the periphery of the aperture.` TvVhile I show the blades tormed with the openings 26, the same result may be accomplished by cutting out that part ot' the blade inside the `opening 26 or by making the blades of other terms, at present7 I preter the form illustrated for the reason that it does not weaken the blade to any extent and the blades o't' the form shown completely exclude the light at the center ol" the aperture when in closed position. 'The blade 22 has the slot 29 formed therein by means of which the blade is connected with the blade `operating member hereinafter more -itully described. An auxiliary blade 8O oil thin material is pivoted to the blade 22 at 27 and adjacent its op-` posite end is slotted as at 30EL to receive a pin 131 secured in the blade 2a? and opera tively connects the blade 2liA with the blade 22 so that as the blade 22 is moved from the closed position shown inFig. 28 to the open position in Fig. 32 the blade 24 is also moved simultaneously from its closed to its open position. A second auxiliary blade 82 is pivoted'at r28 to the blade 22 and to the blade 23 at 83 and operatively connects the blade 23 to the blade 22 to open and close the blade 23 simultaneously with the opening and closing movements of theblade 22. The blade 32 .is provided with the arcuate slotk 34 to provide a clearance for the pivot 25 of the `blade .23. The auxiliary blade 30 is `also slotted at 35 to provide a clearance for the pivot 25 of the blade 24 which engages the auxiliary blade to guide it downwardly and outwardly vas the blades vare opened. The auxiliary blades may be made ot thin material and when the shutter is closed as shown in Fig. 28 overlie` thel enables me to employ a much narrower blade than has heretofore been possible,mal ing possible t-he construction of a high grade shutter ot a size sutiiciently small to be used on small hand cameras without reducing thevk The` flexdiameter of the lens aperture. ibility of the auxiliary blades also serves to take up the" lost motion in the operation of the primary blades and effectively prevents rebound. Pivotally mounted on the partition 2l is the blade operating member or rwhich the blades are closed.

device 88, having a `lug or pin 39 projecting through a slot or opening in the partition 21 and into the slot 29 of the blade 22. l have shown the blade operating member in the present embodiment mounted on auth friction or lball bearings to avoid wear and j insure a smooth rapid movement in the opening and closing movements of the blades. Tol this end the member y38 is counterbored to receive a collar il() which is threaded into it, see Fig. 20. A collar il overlies the outer edge ot the memberBS and is fixed to the partition 2l by means of the screws or Vstuds 4t2. A ball race 'tor the antiltriction balls i8 being formed between the iixed collar 4l and the movable member 3S. A sleeve 40a is threaded into the collar l0 and has a central aperture which receives the pin 40h. An arm la ony the member 38 pro-V jects laterally therefrom and has a member l5 fixedly secured thereto by means ot screws or otherwise. The membeiva extends inwardly over the iixed collar 4,2 and the movable collar 4:3 is provided with the pin t0n and at its inner end is provided with the lug` -or projection .LG 'eccentric to the blade operating member and adapted to be engaged by devices presently to be described to open and close the `shutter blades.

Pivoted `to the partition 2l` is a master member l-T adapted to actuate the blade operating member and also to cooperate with retarding devices for accurately and antomatically controll ing the interval ot tiniebetween the opening and closing movements ot the shutter blades for automatically timed exposures. The master member is also preterably mounted onv antitriction or ball beare ings to illuminate wear and4 permit it to be operated `smoothly at very rapid speeds. For this `purpose the master member com.- prises a collar 4- 8 cooperating with antifriction members or balls 49 ina groove or race provided thereforbetween the member i8 and a stud or postbOlixed to the partition ,2l and on which the master member has a limited turning movement. Formed integral with. 'the collar 4S is a lug orip'rojection 5l which normally engages the inner wall ot' the casing when the master member occupies the position shown in Fig. 5 in motorl spring52 is coiledabout a fixed post 53 and engages a lug or projection 5a on the master member tohold it in normal position with the lug 5l engaging the inner wall ot the casing.A screws or otherwise is an arcuate arm. ex,- tending` around the casing and adapted to engage or cooperate with the retarding devices hereinatter described. Alaterally and downwardly projection finger 5G is formed integral with the arm and is adaptedto cooperate with devices for operating the blade actuating member.V The master mem- A master or I Secured to the collar 48 by los iis

iso

ber is actuated against the tension oil' its spring by devices hereinafter described.

Pivoted to the member by means of a shouldered screw or otherwise is a locking member or dog 51 normally adapted to engage a fixed pin or lug 58 or when moved on its pivot to be disengaged from the fixed pin and to engage the projection 55 to move the blade actuating member to open the blades. A. spring 59 maintains the dog 57 in normal position to engage the pin 5S and lock the blade actuating member` against movement to maintain the blades in closed position until the opening movement for an exposure is about to take place. Vhen the master member is operated 'from the position shown in Fig. 5 to open the blades, the Finger 56 engages a tail member 60 on the dog which is moved against the action ot its spring until the finger 56 passes the dog which is returned to normal position by its spring. During this movement the dogis not moved suniciently to be disengaged ilroin the lug 5S to unlock the blades. Alfter the master member has moved past the dog 57, it is released 'from its operating devices and returned toward its normal position under the action oit its spring 52. During its return movement the linger 5G on the master member again engages the dogr 57 and moves it in the opposite direction against the action ol' its spring until it passes or disengages the pin 58 and releases the blade actuating member so that the blades are l'ree to move to open position. As soon as the dog 57 has moved sufficiently to release the blade actuating member, the dog 57 engages the lug il@ on said member and turns it to open the blades as previously described. The engagement between the finger 56 and the tail G0 of the dog 57 is maintained until the closing movement o'li' the blade actuating member takes place. lNhen the master member has moved su'liiciently to open the blades, vfurther movement in the saine direction operates to agniin nieve the blade actuating member in the opposite direction to normal. position to again close the shutter blades. For this purpose the arm oli the master nien'rber is provided With a lug or projection 6l in position to engage the opposite side oit the lug 46 and upon continued move ment of the master member moves the blade actuating member to vnormal position to close the blades. By means of the construction illustrated and described, I have provided means for locking the blades and maintain.- ing them locked While in closed position7 moreover the parts co-operating to actuate the blade actuating member are so arranged and mounted that the openingand closingmovements ol the blades take place in the shortest possible interval of time. I also provide means for preventing fouling or the actuation ol the operating devices with a click Without producing an exposure resulting in the loss el both the sensitive plate and the picture. For this purpose. the linger 56 is cut away slightly :is at (32 to torni a notch in which the end or the doo` 37 is r adapted to engage when the linger 56 moves opposite the end oilA the dog and holds or locks the parts in this position by reason ot the arrangement the pin and the pivoted centers ot the dog and the master member thus preventing the return el the master member Without operating the blade actuating member to produce an erqposure. Further actuation ot the master member releases it ilrom the dog and permits it to return under the action olf its spring to malte an exposure in the usual manner.

ri trigger is pivotcd to the partition 2l and operatively connected 'with the inaster member. The trigger is preferably mounted on antilfriclion or bali lgiearings to prevent ive-ar und enable it to be operated smoothly at high speed. To this end a pin (il Fig. E51 lined in lhfl partition and a thrust bea 653 serves to space a dis-.lr from the paration. .llie dislc (36 has a l racc in its outer peripheryV adal'ited to rreeive the balls (37 which coinyerato with a similar groove or race in the inner periph- Yformed on the inni-r cnil ery oit a ring (lo of the trigger. '.lhe trigger projects, outnng wall and ivardly through a slot in lthe c; has a linger piece by which it may be main ually operated. A bracket Gl) may he secured to the outer wall of the cursing adjacent the trigger having anV upturned end l() forming a tnumb rest when the trigger is operated and thus avoiding` the danger olf jarring the shutter when operating` it man4 nally. rlhe oppositive end of the bracket also upturned as at 7l and tapped to receive the usual cable release. )i sor-,het or opening 72 lis formed in the trigger `with whichl the end olt the cable cooperates to :in-tuale the trigger. the trigger occupies a position adjacent th. end Tl of the bracket and during operation moves ton'ard the portion "il-llirii'col'.

A. contractile coil snring "2l .is (fourmi-tml with the trigger and anchored to a, post Tl: liXed to the partition and tends to maintain the trigger in its normal position shown in Fig. 5. ""no' from the ilace ol? the trigger is a, pin 75 which projects Cb into a the end of a linlr or connecting member 77 pivoted to the muster member by means ot the shouldered screw 7d. The slot 7U is ol" the 'form shoivn in the drawings having its upper end lorniod with subrsitantially parallel sides slightly inclined and its lower end offset thereto and slightly enlarged.) torming shoulders 79 and SO. A substantially L shaped slot Oil is also formed vin the linl- 77 and a screw or pin 82 substantially conln iti; normal position.

slot`76 provided. there'lfor adjacent centric with the pivot of the trigger projects into this slot and-serves to guide or control the movement of the upper end of the linlr. then `the trigger is moved from the positionv Slioivn in Fig. 5 the lug 75 engages the shoulder 7 9' and moves the link 77 to the position shown in Fig. 6e :it which point the pin 76 rides oit the shoulder 79 and1 into theI upper end ofthe slot as the linlr 77 is moved downwardly under the action of the motor spring 52. and the blade actuating member is actua-ted' to operate the blades.. The stud 82 cooperates with the edges of the slot 81 in the link 77 to limit and guide the movements of the link. A spring 83 is secured to the link and engages a lug or pin 84: lined to the position and tends to maintain the link in fits normal position with the lug 82 to the right of its slot. lVlien the trigger is released! its spring 73 returns it to normal position, duringv which movement the link 77 turns on its pivot Without actuatingl the master member and perinits'the pin 75 to return to normal position in contact with the shoulder' 79 as seen in' 5 ol the drawings.

The parts thus ifar described,v provide a shutter operating automaticallysince a single movement of theA trigger or'of the cable release to move the trigger liist sets the mas ter member and then releases it for an automatic :iposure of instantaneous duration the duration of which depends mainly on the strength of the master or motor spring 52. 1 have alsoprovidedl means for securing accurately timedV automatic exposures of greater duration, and also the so called bulb and time7 exposures. To this end, 1 employ a retarding device oit novel constructionadapted to be assembled a unit before being' placed in the shutter casing and adapted to cooperate with the arm 55 of the master member to delay itsV movement to close the shutter blades at the instant it has moved to open them, These retarding dei vices are particularly' illustrated in Figs. 7

to 16 of the di'aivingsoand comprise a plate or support 85 adapted to be secured in position to thel partition 21' in the casing by means of screws or other suitable means.`

The plate has an opening adjacent one end in `which is received a cylinder or dash pot 80 which normally rests on the partition 21 and has a flange 87 engaging the bottom. ofthe plate 85. Movable in the cylinderor dash pot 86 and closely fitted therein is as piston 88 open atfits outer end and serving as a combined piston cooperating with the dash pot 86 and ai cylinder or dash pot with which a piston 89 cooperates. The plate 85 is provided with a pair olf upstanding flanges 90`ivhich are apertured to receive the pivot pins 91 and 92. Pivoted on the pin 91 is lever 93 apertured to move freely over the dash pot or cylinder 86 and provided With adapted' to engage at di'ametrieally opposite points in a groovey 95 formed inK the outer *Wall of thecombined cylinder and pistony 88 adjacent its outer end. A spring 96 coiled about the pivot 91 is anchored against the plate 85 and engages the lever 93 andV tends* 100 is pivotedy on the pin 92 and extends upwardly and horizontally over the piston' 89 and-then downwardly and again horizontally and" isadaptedteV move on its oivot through theopening 'in the lever ,93 independently of any movement of the latter lever. lThe lever 1`00` is also apertured at 101- to provide a clearance for the post 98 on` the' lever 93. An upstanding post 102 is providedl on the lever 100` for cooperation with the setting devices and a spring 103 associatedr Witlr the pivot of the lever is anchoredagainst the plate 85 and engages tlie'lever to maintain it in normall position with thepost 102v in engagement With" the setting devices. An arm orproje'ction 101A` isbent u-p from the material of the lever 100 and extends into the piston 89 Where'it is provided with'` .an

offset lip 105 Which engages beneath an iny :plate 85 and then secured in position tothe partition 21 in the shutter casing.

Adjustable means are provided for operatively connecting thev master member with the retarding device for controllingthe action of the master or motor springfor securing automatically timed exposures. To fthis end a plate 107'is` pivoted to tlie partition 21 by means of a shouldered screw 108 adjacent the end of the arm of the master member. The endet the plate 107 is provided With a pair ot upstanding flanges 109 in which is pivoted a lever 110 having a curved arm 111 extending beyond the plate 107 and adapted to cooperate With/the levers 93 and 100 iv'hen the plateY 107 is properly adjusted. The other arm of the lever 110 is provided With an" abutmentV 112 adapted to b e engagedby an arm .113 pivoted to a pin or post 111v ixedin the partition 21. The arm 113 is adapted toV be engaged by the arnr 55 of the' `master member which moves" it inone" direction t'o operate'thelever inwardly projecting pins or trunnions 94 Cri kuCt

and a spring` 115 engages the arm to move it in the opposite direction and normally maintains it in contact vvith the abutment 112'oli' the lever 110. fr spring 11G is coiled about the pivot ol the lever 110 and actuates said lever toward the arm 113 which is held in the normal position shown in Fig. 141: by the engagement of a projection 117 on the lever `with the plate 107.

The adjustment ol.' the plate 107, the levers 93 and 100 and the time and bulb levers hereinal'ter described is accomplished by means of settingl devices ot novel construction. Fixed in the partition 21 is a post 118 on which is rotatably mounted a sleeve 119 having; a knurled linger piece 120 at its outer end. rlhe outer or lront lace of the nger piece is provided With a scale bearing the usual indices T, B, 1, 2, 5, 10, 25, 50, 100, and 200, indicating` the exposures time, bulb, 1 second, 1/2 second, 1/5 second, 1/10 second, 1/25 second, 1/50 second etc. A pointer 121 is lixed to the post 118 adjacent the outer lace of the linger piece to cooperate with the scale and serve as a thrust bearing for the sleeve. Fixed on or formed integral with the sleeve 119 are the lever setting,` devices having' the stepped portion 123, 124, 125 and 126 adapted to eng-age the post 98 and set the lever 93 and with it the combined cylinder and piston 88 for exposures of variable duration as hereinafter fully explained. The devices also have the stepped portions 127, 128, 129, 130 and 131 arranged at a greater radial distance from the axis of the sleeve and cooperating with the post 102 of the lever 100 for adjusting' said levell and Wit-h it the piston 89 lor obtaining' automatic exposures ol' shorter duration. Means are also provided for adjusting the member 107 about its pivot 108 bythe setting devices, to move the lever 110 carried thereby 'from a position to engage the lever 100 above for the automatic exposures of short duration to a position to engage both the levers 100 and 93 'tor automatic exposures of longer duration and from the latter position to a position to engage the lever 93 alone lor automatic exposures of the longest duration. For this purpose, I provide a lever 132 centrally apertlu'ed and swiveled on the outer wall of the cylinder 86 in contact with the plate 85 and having; the arm 133 extending' to a point adjacent the setting devices and the arm 12E-fl extending in an opposite direction to a point where it engages the member' 107 which is held in contact therewith by means of a spring' 135 secured thereto and anchored between the inner Wall oli the casing and a lug; 136 fixed to the partition 21. Il desired, the plate 85 may be provided with a flange 137 having' a slot through which the arm 134 extends and which serves as a guide to steady the'movements of the lever 132. The arm 133 of the lever 132 is provided with the lateral projections 138 and 139 the latter olf which is adapted to cooperate With a projection or extension 1110 on the sleeve 119 ol the setting devices, being' held in contact therewith by the action of the sprin` of the member 107 which engages the lever 13.2 and tends to move the arm 133 toward the sleeve 11.9. rlhe llange 90 ot the plate 85 is slotted and the arm and projection .138 project into thisI slot to insure accurate movement ol the lever A32 and maintain it in proper position on the cylinder in contact with the plate 85. With the parts adjusted as shown in Fig'. 7 the setting devices are set for an automatic exposure oit longest duration which the shutter illustrated herein is intended to make, in the present instance one second. 1n this position the point 17 of the scale on the linger piece cooperates 'with the pointer 121 as shown in Fig. 1 and the projection 1110 on the sleeve cooperates Vwith the lever 132 te hold it in the position in Which the arm 111 ol the lever 110 cooperates with the lever 93. At the same time the posts 98 and 102 cooperate directly with the under lace ol the linger piece 120 permitting the levers 93 and 1.00 to move to their l'ull extent under the action of the springs 93 and 103 and the combined cylinder and piston to its 'fullest extent from the cylinder 89 with its bottom wall against the bottom et the piston 89 as seen in Figs. 10 and 11. lt noiv the trigger is actuated to operate the master member Vto cause an exposure as previously described, the linger 56 `first engages the dog` 57 to unlock the shutter actuatinr nt'ember and actuates it to open the shutter blades, at this instant the lug G1 on the arm engages the lug 46 to return the blade actuating member to close the shutter but the arm engages the retarding devices which prevent the liree movement ot the master member to close the shutter blades until the retardinn' device has been actuated. To this end, the end of the arm 55 of the master member has a downwardly projecting lugr 141 in position to engage the arm 113 .vhei'i the master member is actuated. As the mas ter member moves from its normal position in Fig. 5 to set position Fig'. G the lug 141 moves the arm 113 idly against the action ot its spring; but whenv moving in the opposite direction, it moves lireely until the shutter blades have been opened as 'above described When the lueY til-1 :xr-ain engages the j arm 113 on its opposite side and through the arm swing-s the lever 110 against the action et its spring; and the lever 93 associated with the combined cylinder and piston 88 and actuates said lever from the position shown in Fig'. 11 to that shown in Fig. 12, at 'Which time the lun; 141 moves oli' the end of the arm 113 and permits the motor s ning to move the masteV member to close the shutter blades. will be noted that in its movev nient from the F 111position to that shown in Fig. 12 the lever'93 movesthe cylinder `88 against the action of the piston 89 andalso against the action of lthe cylinder' 86 resulting in a retarding action on the master memher equivalent to the combined retarding capacity ot the cylinders 86 and 88.- It Will he understood that the maximum retardlng acytion can readily befinereased by increasing the capaci'ties'of thecylinders 86 and 88. To secure shorter vexposuresit vis necessary to utilize only a proportional part of the capacity oi rthe cylinders 86 and 8S and 'for the shortest exposures to eliminate their action altogether. By moving;- the linger piece T120 to bring tli vpoint 2 o1 yits scale to the` pointerl for an exposiu'e oif`1/2second, the lever 110 remains in position indicated Y for -one second, hut a stepped portion 125er-cani 126 ot the setting devicesengages the post 98 on tli'eleiferfll and depresses said `lever from the position shoivuin Fig." 191, to limit the movement of the post 98 `outWardly toward the linger piece 120 and depressing the `comhined cylinder and pieton 88 and .liinitingits stroke with the result that only a part oltlie i'ull csjrpecity oi the retardingdevices now employcd7 resulting'in the present instance in an exposure (rtl/2 second. If the finger piece is further rotated to bring the index o oi Vthe scale under the pointer afsccond stepped portion engages thel postQS and lurtl-ier depresses the'lever 93, a stepped portion also engages thepost 102 and depresses the lever 1GO untilitsfoutelr end is ymoved into theplace of the outer end' or the lever 93,' at thisftime' the'projectionV 14() is also moved to permitthe sjn'ing` tomove the lever 110 to `a `positionr Where it engages both levers 93 und 100. 'In this `position ot the parts ythe piston S rests on the bottom of the cylinder 88 and thel lever 110 engages and operates, both leversfQF-J and 100 simultaneously utilizing` onlya small part of the retarding capacityioit the cylinder 86 resulting in the present instance in-an exposure of l/ of a second.4 Still. further rotation oftl'ielin- `ger piece 120,l untilthefindexlcooperates with the pointer 'for an exposure of l/lOth of a secoinil,` releases the lever 100 `from its stepped member and permits `it-to return to its outer vposition` shown in Fig. '12? of the drawings. rlhe lever further depressed to its lfullj extenthy the cooperation of the steilnjedportion or canrmemher 12A- with its postl 9S and the projection 14() -disengages the lever 133 and permits the spring, 135 to more the lever 1l() toa position to engage 'the lever 1GO/along;V in which `position it operates independently oit the lever 9B. It will he noted that in this vposition of the partsy the retardingv action of the small cylinder 88 and pistonl 89 are 'along utilized and With the capacity of the parts5 as illustrated, results in an exposure of l/lOth of a-second. Still 131V with the post 102 of 'the lever 1GO. Ink

this position ofthe parts the retarding action is limited to a' portion of the capacity of the'sniall cylinder 88 and :in `the present instance results in an exposure o'l 1/25th `of a second.` `Further rotation o'l the finger piece 120 to bring the index 50 thereon into cooperation With the pointer to adjust thev parts for anexposuie'ot 1/50th ol a second, causes" the lstepped portion 130 or the setting devices to 'further depress the lever 1GO to'limit its movement still further until an exposure of thedesired time 1/50thof a As the second is obtainedy yStill further movement the vlever reducing' the retarding action ol the cylinder 88 to a small fraction only of itsv capacity, resulting` inthe desired exposure t lwill understood that during these last setting operations theleversr 'and 93 remain stationary, the former heini; i v

in position to engage the lever 100 and the latter being; depressed to itslimit to eliminate the lretarding action of the cylinder 86. tfvvill also be noted thatl have provided a retarding device comprisingv a plurality of cylinders and pistons of different capacities in which the Yliull'capacity oit all the cylinders'isiitilized 'lorautomatic exposures of longerduration., the liull and fractional parts of thefapacity oi the larger cylinder being utilized for ex iosures of intermediate'lenoth i or duratiori, and the lull and fractional parts olf the capacity the smaller piston being` utilized lfor automatic exposures olf shorter duration, the retardi-ng action being entirely elin'iinated for an exposure oit the shortest dumtionl as whenthe linger piece -is rnovef tobring its index 200 ttor an exposure` 1/200th oli a second `into cooperation withthe pointer, the portion 128 of the setting" devices, again engagesr tlie'post 102 and moves the parts to the position sliov'n in Fig'. 13 in .whichV lthe levers 93 and 100 are hoth depressed to their limit and the lever 110 is freel tofsivino on its Divot without )actuatin' l eithenof them or appreciahly ietardingthe movement oi the master member.

I havey also provided means tork securing Whatis known time and bulb expo sui-es'.l lVlien the linger piece 120 is turned ter for any required exposure Without danger of disarranging the parts or getting them out orl order. For this purpose, the posts 98 andlOQ have rounded or spherical engaging portions oooperating with the oomparatively short steps of the setting devices, and the time and bulb levers engage the setting devices with a wiping aetionvvhieh does not interi'ere with the ree rotation oi the finger' ce in either direction. i i

llavingdeseribed my invention, what I.

claim and desire to secure by Letters Patent is; i ,A y

l. In a shutter, the combination of a easing having an aperture therethrough, a `plurality of blades pivoted insaidoasing i'or `opening' and closing said aperture, .said

blades being provided With openings ada-pt- `ed to admitl light trema plurality of marginal openings simultaneously Withthe admission of light `from the Center opening while the light is obstructed 'in a riaigaround the Center opening during the opening and Closing movements of the blades, andmeans for opening and closing the blades.

l2. In a shutter, the combination of a oasing'having an aperture there through,

plurality of blades movably mounted in said easing ior opening and elosingsald aperture, eaeh of saidd blades havingan opening for admitting light from the margin of the aperture simultaneously with the admission of light from the center thereoif during theopening and Closing movements. of the blades, and means tor moving the blades.

S3. ln a shutter, the combination oit a oasing having an aperture there through, a plurality oil blades pivoted in said casing for opening and closing said aperture, a plurality el" auxiliary blades connecting said blades ifor causing them to move simultanei ously,-and means operatively ooi'meoted With one. ol said blades for moving it.

t. Ina shutter, the combination of a oasing having an aperture `there, through, a

plurality ot blades pivot-ed in said easing tor opening and elosing said aperture, a plurality olEV auxiliary blades eonneeting said blades for Causing them to move simultaneously and cooperating therewith to present the admission oie reflected light through the aperture when the blades are in closed position, and means operatively Connected with one olisaid blades `for moving it. y

ln shutter, the combination of a oasing having an aperture there through, a plu- `rality of blades pivoted in said easing for opening and 'closing said aperture, a plurality of auxiliary blades Connecting` said blades ior causing them to move simultaneously, tail members on said auxiliary blades adapted to Cooperate `with; the primary blades to exclude refieoted light from the aperture `When the blades are in closed .posiloperatively connecting said blade `with the on said auxiliary other blades, means blades adapted to V'eo'operate with said bladesto exclude reflected light from the aperture when the blades are in 4closed position, and meansoperatively yconnected with one off said blades tor moving it.

7 .n In a shutter, the combination of a `ing having an 'aperture there through, a 'plurality ,of blades movably mounted `in said easing for opening and closingy said `aperture, a blade `operating member pivotalily mounted in said casing and operatively oon neo'ted with said'blades, a master member operatively engaging said Vblade operating member, a` motor spring for yactuating the mastermember, a trigger, and fa link opera tively connecting the Atrigger with the master member for `tensioni-ng the motor Spring, said link being automatically released from the trigger to permit the `spring to aotuate the master member.

8, In a shutter, the combina-tion of a oas i inghavingfan aperture there through, a plus ralityof blades Lmovably mounted in said easing for opening and closing said aperture, la blade operating member pivotia'lly ymounted in said easing and operatively oonneeted with said blades, a master member olvierative-lyA` engaging said blade operating ing Ahaving an aperture there through, a lplurality of blades movably mounted in said easing for opening and yclosing said `aperture, a `bla-de Voperating member pivotally mounted in said easing and operatively con neeted With said blades, a master member operatively -oonneeted With 'the blade operating member, and a 'trigger pivoted in said easing and operatively eonneeted with the master member, said-blade.operating member, master member and `trigger all 'being mounted on antifrietion bearings to enable them `to be operated quickly at high speed.

l0. In a shutter, the combination of a easing having anaperture there through, a plu rality oit blades movablymounted in :said

easing `tor opening and closing said aperture, a `blade operating member pivotally mounted in said easing and operatively oonneoted With said blades, a master Amember operatively vconnected With said blades, a

motor spring for actuating the master member, a trigger pivoted in said casing, a link pivoted to the master member, and a pin and slot connection between the link and the trigger adapted to connect the link to the trigger to tension the motor spring and automatically release the link from the trigger to permit the spring to actuate the master member.

l1. In a shutter, the combination of a casing having an aperture there through, a plurality of blades movably mounted in said casing tor opening and closing said aperture, a blade operating member pivotally mounted in said casing and operatively conneoted with said blades, a master member operatively connected with said blades, a motor spring for actuating the master member, a trigger pivoted in said casing, a link pivoted to the master member, having a substantially L shaped slot and a projection on said trigger in said slot adapted to operatively connect the link with said trigger, the construction being such that the pin lirst engages the shoulder in the slot to actuate the link to tension the motor spring when it rides ol the shoulder and permits said sprin to actuate the master member.

l2. In a shutter, the combination oit a casing having an aperture there through, a plurality of blades movably mounted in said casing for opening and closing said aperture, a blade operating member pivotally mounted in said casingand operatively connected With said blades, a master member operatively engaging said blade operating member, a motor spring Ator actuating the master member, a trigger pivoted in said. easing, a link pivoted to the master member, means on said trigger adapted to operatively connect the link with said trigger, the coustruction being such that actuation ot the trigger actuates the master member to tension the motor spring when the link is automatically released to permit the master member to actuate the shutter blades, and a spring Yfor returning the trigger, to normal position.

ln a shutter, the combination of a easing having an aperture there through, a plurality of blades movably mounted in said casing for opening` and closing said aperture, a blade operating member pivotally mounted in said casing and operatively connected with said blades. master member operatively engaging said blade operating member, a motor spring for actuating the master member, a trigger, a link operatively connecting the trigger with the master member, and means cooperating with said link to arrest the movement of the master member to close the blades While the trigger is depressed.

le. In a shutter, the combination of a casing having an aperture there through, a plu- ,rality of blades movably mounted in sau rality of blades movably mounted in said casing `iter opening and closing said aperture, a blade operating member pivotally mounted in said easing and operatively connected 'with said blades, :i master member operatively engaging said blade operating member, a motor spring tor actuating the master member, a trigger, a link operatively connecting the trigger with the master niemher, a bulb lever cooperating with said link to arrest the movement ot the master member to close the blades While the trigger depressed, and means ttor moving the bulb lever to inoperative position.

l5. In a shutter, the combination of a casing having an aperture there through, a plurality oit blades movably mounted in said casing for opening and closing said aperture, a blade operating member pivotall).v mounted in said casing and operatively connected With said blades, a master member operatively engaging said blade operating member, a motor spring for actuating the master member, a trigger, a link oijieratively connecting the trigger with the master member, a bulb lever having an nrni adapted to cooperate with the link to arrest the n'iovement of the master member to close the blades While the trigger is depressed, and settingdevices operatively engaging the other arm oli the bulb lever :tor moving said lever to an inoperative position.

16. In a shutter, the combination ot a casing having an aperture there through, a plurality ot blades movably mounted in said casing ttor opening and closing said apex`- ture, a blade operating member pivotally mounted in said casing and operatively connected with said blades, u master member operatively engaging said blade o'ierating member, a motor spring t'or actuating the master member, a trigger, a link operativel v connecting the Vtrigger with the master meinber. setting` devices, and a bulb lever cooperating with the link to arrest the movement of lthe master member to rlose the blades While the trigger is depressed. and having a wiping engagement with the setting devices to permit tree movement thereof in either direction.

17. In shutter, the coinbination of a casing` having an aperture there through, a plul casing for opening and closing said aperture, blade operating member pivotally mounted in said casing' and operatively connected with said, blades, a master member operatively engaging said blade operating member, motor spring for actua-ting the master member, a trigger. a link operatively connecting the trigger with the master member, a lug on said link, a bulb lever adapted to engage said lug, and a spring for holding said bulb lever in operative position, the construction being such that when the trigl operating membe ger Ais depressed, the lug engages the lever and moves it idly from its path butcn the` i return movement oi the link engages the lug lug from the bulb lever and permits tree movement of the master member to 4close the blades. t Y

18. In' a shutter,`the combination oft a casing having an'aperture there through, a plurality of blades movably mounted in said easing for opening and closing lsaid aperture, ablade operating member pivotally mounted in `said casing and operatively engaging said blades, a 'master member operatively engagingsaid blade operating member, 'a motor spring for actuating the master member, a trigger, a link operatively eoir necting the trigger tion ot' the trigger lirst tensions the motor spring When the link is automatically released to permit the master member to move to open and close the blades, and means cooperating With the link to lock the master member against further movement ivlien the blades are open, a second actuation 4ot `the trigger operating to release the link to per-y `mit further movement of the master member to close the blades. y y

19. In -a shutter, the combination ot a casing havingV an aperture there through, a

plurality ot blades movablymouiited in said casing tor opening and closing said aporture, a blade operating member pivotally mounted in said casing and `operatively conf iiected With 4said blades, `a master member `operatively engaging said blade'operating adapted to engage the link and lock the lmaster member against further movement when the yblades are open and bulb lever cooperating with the link to `direct it into engagement with the time lever.

20. In a shutter, the combination of `a casing having an aperture there through, a plurality of blades'movably mounted in said "casing for openingn and closing said apen ture, a blade operating member pivotally mounted `insaid Icasing and operatively connected with said blades, a master membery operatively engaging said blade al motor spring tor actuating the master member, a trigger,

a link operatively connecting the trigger with the master member, the construction withF the master menr' ber, the construction being such that actua being such that actuation of theptrigger tiret tensions the motor spring when the .linkis automatically released to permit the master member to move to open and close the blades, a time lever adapted to `engage the link and lock the master member against `further movement when the blades are open, a bulb lever cooperating with the link to direct into engagement with the time lever, and setting devices for `moving said levers to inoperative positions.

231.111 a shutter, `he combination ot a casing having an aperture there through, a plurality oit blades movably mounted in said casing ioi opening `and closing said aper ture a blade operating member pivotally mounted in said casing and operatively connected With said blades,` a master member operatively engagiiio` vsaid blade operating iinember, a motor spring or actuating'the movement when the blades are open and` having a wiping engagement With the setting devices to permit tree rotation thereoi in either direction, `and a bulb lever cooper-v ating with the link to direct it into locking engagement with 'the time lever.

22, ln a shutter, the coml-iinatioii ot a cas-- ing having au aperture there through,a pluiality oi' blades niovably mounted iii said casing toicpi-mingY and closing said aperture` a blade operating member pivotally mounted iii said casing and operatively icon- -necte(l.ivi.th said blades, a master member operatively cngagingsaid blade operating incinbei", a motor spring 'for actuating `the .master iiieii'ibei, ati ejer, a link operatively connectiiiig the trigger *with the master member, the construction being such that actuation ot the trigger inirsttensions the motor spring when the link is automatically released to `per iit the master member to move to open and close the blades, a time lever, a hook on the time lever adapted to eiieaffje the linl'; and lock the master member against tui-ther movement when the vblades are open, and a bulb lever cooperating with the link to direct it into engagement with the hook.

In a shutter, the combination vof a 'casf ino; having an aperture there through, a

plurality ot blades inovably mounted in said casing for opening and/closing ksaid aperture, a blade operating member pivotally mounted in said casing and operatively conllO member, a motor spring for actuating the master member, trigger, a linlr operatively connecting the trigger with the master member, the construction beingl such that actuation ot the trigger first tensions the motor spring when the link automatically released to permit the master member to move, to open and close the blades, a time lever, a hook on the time lever adapted Vto engage the link and lock the master member against` Ytur-- ther movement when the blades are open, setting devices cooperating with the time leve for moving the hook to inoperative position, and a bulb lever adapted to engage the link and direct it into engagement with the hook,

24C. In a shutter, the combination of a casing having an aperture there through, a. plurality of blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected with the blades, a master member, a motor spring for actuating the master member, means operated by the master member under control of the motor spring tor moving the blade operating member in two directions to open and close the blades, and means 'for tensioning the motor spring.

25. In a shutter, the combination of a casing having an aperturethere through, a plurality of blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected with the blades, a master member, a motor spring for actuating the master member, a lug lined on the blade operating member, a dog` pivoted on the blade operating member, and a ringer on the master member adapted to swing the dog into engagement with the lug to move the blade operating member to open the blades.

26. In a. shutter, the combination oi a casing having an aperture there through, a plurality of blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected with the blades, a master member, a motor spring 'for actuating the master member, a lug fixed on the blade operating member, a dog pivoted on the blade operatingI member, a linger on the master member adapted to move the dog into engagement with the lug to move the blade operating member to open the blades, and an arm on the master member adapted to engage the lug to nieve the blade operating member in the opposite direction to close the blades.

27. In a shutter, the combination of a casing having an aperture there. through, a plurality of blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected. Wi th the blades, a. master member, a motor spring for actuating the master member, a lugI iiXed in the casing, a dog pivoted on the blade operating member, and normally engaging the fixed lug to loclr the blade operating member against movement, a lug on the blade operating member and a inger on the master member adapted to engage the dog Vand move it out ot engagement with the tified lug to unloelr the blade operating member and into engagement with the lug on the blade operating member to move the blade operating member to open the blades.

28. In a shutter, the combination ot a casing having an aperture there through, a. plu-- ral ity ot blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected With the blades, a master member, a motor spring 'for actuating the master member, a lug lined in the casing, a dog pivoted on the blade operating member and normally engaging the fixed lug to lock the blade operating member against movement, a lug on the blade operating member, and linger on the master ,member adapted to engage the dog and move it idly out of its path Without dr:l ngaging it from the fixed lug When the master member moves to tension the motor spring and to engage the dog when the. master member returns under the action oli the motor spring to move it out ol engagement with the fixed lug and into engagement with the lug on the blade operating member to move the latter to open the blades.

29. In a shutter, the combination ot' a casing having an aperture there through, a plurality or' blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected with the blades, a master member, a motor spring tor actuating the master member, a lug fixed in the casing, a dog pivoted on `the blade operating member and normally engaging the 'fixed lug to loclr the blade operating member against movement, a lug on the blade operating member, a finger on the master member adapted to engage the dog and move it idly out of its path Without dis-'engaging it from its 'fixed lug when the master moves to tension the motor spring and to disengage the dog When the master member returns under the action of its spring and move it out of engagement with the tired lug and into engagement with the lug on the blade operating member to move the latter to open the blades, and a spring ior holding the dog in normal position to engage the lined lug.

30. In a shutter, the combination of a casing having an aperture there through, a plurality oit blades movable therein to open and close the aperture, a pivoted blade operating member operatively connected with the blades, a master member, a motor spring for actuating the master member, a lug fixed in the casing, a dog pivoted on the blade operating member and norm ally engaging the fixed lug to lock the blade operating member against movement, a lug on the blade operating member, and* means on 'the master member adapted to engage the dog and move it idly irom its patli without disengaging it from the i'ixed lug when the master member moves it one direction and to move the dog out oi: engagement with the lined lug and into engagement Withthelug on the blade operating member'to move said men'ibertoopen the blades When the master membe-r moves in the. opposite direction. 1

31. liia shutter, the coinibinationv ol' al casing having an aperture there through, a 'plu-v rality of blades movable therein to fopen and close the aperture, a pivoted blade operatiii-g member operatively connected With the blades, a master member, a motor spring for actuatii'ig the master member, a lug fixed in.

the casing, a dog pivoted fon the blade operating member, and normally enga-ging the fixed lng to loclr the blade-operating niemberagainst movement, a lug on the blade operating member, and means on the master member adapted to engage thedog and move it idly from itsy path When the master inember moves in one directionand to move it out of engagement with the iiXed lngy and into engagement with the lug on the blade opierating member to open the blades ivlienit moves in the opposite direction, the relation ot the Ytiered lug and the pivots of the dog master member ttor actuating the blade operating member to open and close the blades,

and retarding devices ior preventing the' 'tree movement ot the master member to close the blades.

ln shut-ter, the combination of a casi having an aperture therethrough, blades movably mounted inthe easing ttor opening and closing the aperture, a blade operating member for opening and closing the blades, master member for actuating `the blade operating member, a motor spring for the master member, a trigger operatively connected with the master member for tensioning the motor spring.` and retarding devices operatively engaged by the master member during its movement to close the blades.

311-, ln a shutter, the combination of a casing` having an aperture therethrough, blades movably mounted in the casing for opening and closing the aperture, a blade operating member opening and closing the blades, a master member ior actuating the blade operating member, `a motor spring :tor the master member, a trigger operatively connected with the master member for tensioning the motor spring, an arm on the master member, retard-ing devices, and an arm pivoted in the shutter casing operatively en-` gaging the retardi-ng devices andengaged by 'the arm onV the iiiaster memberwhen'the f blades.

`35` In a shutter, the combination ot a casing having an aperture therethrough, blades master member moves to close the shutter moi'fablymounted in tliecasing for opening andI closing the aperture, a bladey operating member tor opening and closing the blades,

a master member 'for-.actuating the bladek operating member, a motor spring ttor the niastei*member, a trigger operatively connected 'With the master member for tensioning the motor spring, retarding devices, an arm pivoted in the shutter casing and operatively engaging the retarding devices and an arm on the master ymember adapted to engageV the pivoted and move it idly out of itspath When the master member moves to tension the motor spring and to engage the pivoted arm to operate the retardi-iig devices when the master member moves to close the shutter blades.

`36. In a shutter, the combination oi a cas- Ying having an aperture therethrough,blades tor opening and closing the aperture, aY inaster member for actuating the blades, and a ietarding device cooperating with the master memberand comprisinga cylinder having its axis substantially parallel with the axis or the casing aperture and a piston cooperating with the cylinder. i i

37. En a shutter, the combination of a casing having an aperture therethrough, blades Jfor opening and closing` the aperture, a master member for actuating the blades, and a retarding device cooperating vviththe master member and comprising a combined cylinder and piston cooperating with a cylinder and a piston. l

S8. In a shutter, the combination of a casing having an aperture therethrough, blades for opening and' closing the aperture, amaster member for actuating they blades, and a `retf/irdi-ng device cooperating with the master membery and comprising a combined cylinder and piston,a piston cooperating therewith, and means iorliiniting the stroke of the piston in the cylinder. i

39. In a shutter, the combination oit a casing having an aperture therethrough, blades for opening` and closing the aperture, a master member for actuating the blades, and a retarding device cooperating with the master member and comprising a combined cylinoer and piston, a lever associated there- With, and setting devices 'for 4limiting the movement of the lever.

llt). In a shutter, lthe combination oit a caslio ing having an aperture therethrough, blades for opening and closing the apertui'e, a master member or actuating the blades, and a retarding device cooperating With the master member and comprising a combined cylinder' and piston, a lever associated therewith, setting devices, and a post on said lever havii'ig a portion adapted to engage said setting devices.

ll. In a shutter, the combination o1 a casing having an aperture therethrough, blades :for opening and closing the aperture, a master member vfor actuating the blades, and a retarding device cooperating` with the mastei' member and comprising a combined cylinder and piston, a piston cooperating there with, a lever associated With said combined cylinder and piston, a lever associated with said piston and independent of said first named lever, and setting devices cooperating with said levers.

42. In a shutter, the combination of a case ing having an aperture therethrough, blades 'for opening and closing the aperture, a mas ter member 'for actuating the blades and a retarding device cooperating `with the master member and comprising a cylinder, a piston cooperating therewith, a lever associated with the piston, a post on said lever, and setting devices engaging said post and adapted to depress the lever to limit the stroke oi'' the piston.

43. In a shutter, the combination oi' a casing having an aperture therethrough, blades vfor opening and closing the aperture, a master member 'for actuating the blades, a lever operatively engaged by the master member, retarding devices operatively ens gaged by said lever and setting devices' adapted to adjust said lever relatively to the retarding devices.

441-. In a shutter, the combination or' a casing having an aperture therethrough, blades ttor opening and closing the aperture, a master member for actuating the blades, a lever adapted to be operated by the master member, retarding devices comprising tivo independently movable levers and means 'for adjusting the first mentioned lever 'from a position to engage both of said retarding levers to a position to engage one only thereof.

45. In a shutter, the combination oit a casing Ihaving an aperture therethrough, blades for opening and closing` the aperture, a master member lor actuating the blades, a lever adapted to be operated by the master member, retarding devices comprisin r a lever adapted. .to be engaged by said .first mentioned lever, and means for adjusting said first mentioned lever out oit engagement with the second lever.

'-16. In a shutter, the combination of a casing having an aperture therethrough, blades Laar-anco 'for opening and closing the aperture, a maste' member ilor actuating the blades, a lever adapted to be operated by the master member, retarding devices operatively engaged by said lever, a movable plate on ivhich said lever is mounted, and means for moving said plate to vary the position of said lever relatively to the i'etarding devices.

il?. In a shutter, the combination ol a casing having an aperture therethrough, blades lier openino` and closing the aperture, a master member ior actuating the blades, a lever adapted to be operated by the master member, retarding devices operatively engaged by said lever, a movable plate on which said lever is mounted, setting devices cooperating with the retarding devices, and means operatively engaging said movable plate and setting devices tor moving said plate to vary the position or said lever relatively to the retarding devices.

a8. In a shutter, the combination oil? a casing having' an aperture tlierethrough, blades for opening and closing the aperture, a master membelI 'lor actuating the blades, a lever adapted to be operated by the master member, retarding devices comprising a cylinder and a lever operatively engaged by said first mentioned lever, a pivoted plate on which said :lirst mentioned lever is ml'iunted, setting devices lcooperating with the retarding devices, and a lever suiveled on said cylinder and operatively cininecting said pivoted plate with the setting devices.

a9. In a shutter, the combination or' a casing having an aperture thcretluough, blades for opening and closiiiig the aperture, a master member for actuating the blades, a pivoted arm adapted to be engaged by the master membe a lever engaged l y said arm, retarding devices operatively engaged by said lever,y and setting devices cooperating with said retarding devices and adapted to vary the position oli said lever relatively thereto.

50. il retarding device :tor a shutter ycomprising a supporting plate adapted to be secured in the shutter casing. a cylinder se4 cured to the plate, a piston. cooperating with said cylinder` and means associated with said piston and adapted to cooperate with the blade actuating devices oit the shutter,

5l. A. retarding device 'ifor a shutter coni-v prising a supporting plato, a cylinder secured in said plate, a piston in said cylinder and lever pivoted to said plate, and operatively connected to said piston and adapted to be operated by 'the blade actuating devices of the shutter.

52. A retarding device for a shutter comprising a supi'iorting plate. a cylinder se cured in said plate, a piston in said cylinder, a .lever pivoted to said plate and o'ierativcly connected to said piston and adapted to be operated by the blade actuating devices, and

a spring for moving the lever to normally Withdraw tlie piston from tlie cylinder.

53. A retarding device tor a shutter comprising a supporting plate, acylinder secured in said' plate, a piston .in said cylinder,

a lever pivoted tol said plate and operatively connected to said. piston, and setting devices piston in said cylinder, a piston in saidl combined cylinder and piston, and means for operatively connecting said combined cylinder and piston and piston with tlie vblade actuating devices `of the shutter.

55. A retarding device for a. shutter comprising a supporting plate, a cylinder' secured in said plate, a combined cylinder and piston in said cylinder, a piston in said combined cylinder and piston, and means for operatively 'connecting said piston with the blade actuating devices of the shutter.

56. A retarding device 'tor a shutter comprising a supporting plate, a cylinder secured in said plate, a combined cylinder and piston in said'cylinder, a piston in said combined cylinder and piston, and a lever operatively connected with said piston and adapted to be operatively engaged by the blade actuating devices of the shutter.

57. A i retarding device for a shutter comprising a supporting plate, a cylinder secured in said plate, a combined cylinder and rpiston in said cylinder, a piston in said combined cylinder' and piston, a leverI` operatively connected ivitli said piston and adapted to be operatively engaged by the blade actuating devices off the shutter, and setting devices cooperating with said leven 5S. A retarding device for a shutter comprising a supporting plate, a cylinder secured in said plate, a combined cylinder and piston in said cylinder', a piston in said conlbined cylinder and piston, a lever operatively connected Witli said piston, a spring for moving the lever tol withdraw the piston i from the combined cylinder and piston, and means adapted to maintain tlie` piston in a plurality ot set positions relatively to the cylinder.

59. A retarding device for a shutter comprising a supporting plate, a cylinder secured in said plate, a combined cylinder and pistonin said cylinder, a lever operatively connected tlierevvitli, a piston in said combined cylinder and piston, a lever operatively connected with said piston, and setting devices cooperating` with said levers 'for independently adjusting tlie'piston relatively to the combined cylinder and piston and the combined cylinder and piston relatively to its cylinder.

A -retarding devicey fory a shutter comprising a supporting plate, a cylinder secu-red in said plate, a combined cylinder and piston in said cylinder, ay lever `operatively connected therewith, a piston .in said combined cylinder and piston, a lever operatively connected with said piston, an adjustable lever adapted to selectively engage said `levers and operated by the blade actuating devices oilI tlie shutter, and means for adjusting said last named lever. Y

6l. A. retarding device 'l'for a shutter comprising a supporting plate, a cylinder secured in. saidfplate, combined cylinder and piston in said cylinder', a lever operatively connected therewith, a piston in said coinbined cylinder' and piston, a lever opera-v tively connected vvith said piston, an adjustable lever adapted to selectively engage said levers and operated by the blade actuating devices of the shutter, and a lever mounted on said cylinder for adjusting said adjustable lever.

62. ifi. retarding device 'for a rshutter comprising a supporting' plate, a cylinder secured in said plate, piston in said cylinder, a lever operatively connected with said piston, a lever adapted `to engage said lever and operated by tlieblade actuating devices ofthe shutter, and means for moving said last named lever into and Aout of a position to engage said first named lever.

A retarding devicey for a shutter coi'nprising a supporting plate, a cylinder secured insaid plate, a combined cylinder and piston in saidcylinder, a lever operatively 64.1K retarding device for a shutter` engagi'n said combined cylinder and piston,

a piston in said combined cylinder and piston, a lever operated the blade actuating devices ot the shutter and adapted to engage said first named lever, and means tor adjusting said `last named lever into and out ci engagement rWith said firstA named lever. i y

65. Ai `retarding device for a shutter comprising a supporting plate, a cylinder secured in said plate, a combined cylinder and piston in said cylinder, a lever operatively engaging said combined cylinder and piston, a piston in said combined cylinder and piston, a lever operatively engaging said piston, a lever operated by the vblade actuating devices oil tlie sliutter and adapted to engage the first named lever to actuate the combined cylinder and piston in its cylinder and against its piston' in the combined cylinrio 

